1. Field of the Invention
This invention relates to gravity-sensitive switches used in electrical systems. More particularly, it relates to a gravity-sensitive switch featuring a shiftable magnet.
2. Description of the Prior Art
Gravity-sensitive switches employing conductive rolling balls, optical detectors utilized with shifting apparatus, mercury switches and the like have long been used for various purposes.
Switches utilizing magnets are preferable to mercury switches for environmental and safety reasons, as well as for simplicity of design. Magnets used in conjunction with reed switches, however, tend to be bulky because of the magnet size required to effectively overcome the coefficient of friction (i.e. the weight and corresponding size of the magnet must be such that the device is gravitationally sensitive). The size of the magnet can in turn cause unwanted magnetic side effects in the operation of the mechanism. The magnets used in these gravity-sensitive apparatus are also typically completely enclosed. The enclosure aspect of the apparatus leads to undesirable moisture and contamination problems within the casing housing the magnet.
What is needed is a magnetic apparatus (suitable for use with a reed switch or the like) which is relatively small yet gravitationally sensitive. Also needed is an apparatus wherein the magnet is not completely enclosed so that moisture and contamination problems are avoided.